1225521520 has 40 divisors (see below), whose sum is σ = 2853861984. Its totient is φ = 489430272.

The previous prime is 1225521487. The next prime is 1225521523. The reversal of 1225521520 is 251255221.

It is a tau number, because it is divible by the number of its divisors (40).

It is a super-2 number, since 2×1225521520² = 3003805991966220800, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1225521523) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 39922 + ... + 63598.

Almost surely, 2^1225521520 is an apocalyptic number.

1225521520 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1225521520 is an abundant number, since it is smaller than the sum of its proper divisors (1628340464).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1225521520 is a wasteful number, since it uses less digits than its factorization.

1225521520 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 24337 (or 24331 counting only the distinct ones).

The product of its (nonzero) digits is 2000, while the sum is 25.

The square root of 1225521520 is about 35007.4494929294. The cubic root of 1225521520 is about 1070.1393011640.

Adding to 1225521520 its reverse (251255221), we get a palindrome (1476776741).

The spelling of 1225521520 in words is "one billion, two hundred twenty-five million, five hundred twenty-one thousand, five hundred twenty".